The Dutch artist -- seven of whose works are among the 30 most expensive paintings ever sold -- is thought to have made the ink drawings in the accounts book of a hotel he was staying at in the southern French city of Arles.
Although the originals were not shown at the Paris press conference to announce the discovery, a book reproducing the drawings, "Vincent Van Gogh, the fog of Arles: the rediscovered sketchbook", will be published on Thursday in France, the US, Japan, Britain, Germany and the Netherlands.
The forgotten works created at end of Van Gogh's tormented life between 1888 and 1890 include portraits of his friends the artist Paul Gauguin and Pierre and Marie Ginoux, who owned the famous Cafe de la Gare where he stayed.
Van Gogh immortalised Marie -- with whom he had a strong bond -- in one of his most famous paintings, "L'Arlesienne" (The Arles Woman). The accounts book belonged to the Gafe de la Gare, and he sketched in it as he produced some of his greatest paintings, including "Bedroom in Arles", "The Night Cafe", "Van Gogh's Chair" and "Still Life: Vase with Twelve Sunflowers".
Le Seuil described the sketches, which come from the most important period in the artist's life, as "a very impressive ensemble" and insisted that "their authenticity is well established".
It said that the accounts book was found in the archives of the Cafe de la Gare.
The Van Gogh Museum, however, said on Tuesday that the drawings were imitations, saying its experts had long been aware of the notebook, and on the basis of being sent 56 photos of 65 of its drawings "they were of the opinion that these could not be attributed to Vincent Van Gogh".
"Their opinion, based on years of research on Van Gogh's drawings ... is that these album drawings are imitations of Van Gogh's drawings," the museum said in a statement:
"The experts examined its style, technique and iconography, and among their conclusions were that it contains distinctive topographical errors and that its maker based it on discoloured drawings by Van Gogh."
The museum added that another clue debunking the authenticity of the notebook was that the drawings "are executed in brownish ink, and this type of ink has never been found in Van Gogh's drawings from the years 1888-1890."
Most of the sketches in the book are of the Provencal countryside around Arles where Van Gogh painted furiously over the period of his year-long stay there.
It was after a fight with his friend Paul Gauguin on December 23, 1888, that Van Gogh cut off part of his ear. His "Portrait of Dr Gachet", which dates from this period, sold for 77 million euros in New York in 1990. Experts estimate that it would go for about twice that today if it came to auction.
- with AFP